Internal-combustion engine



H T T lm C. om 2 9 11 4 a e D INTERNAL COMBUSTION ENGINE Filed March` 16. 1922 r2) Sheets-Sheet 1 www@ 5 2 0 .Tu S M w W 1 m f S HMI In 2 ,M m q/M/ E HNw #4 MMM www uw wh nu! ...mm i .Ca S M i cTAud In NE ma Ei TF m 2 9 1 4 a e D Patented Dec. 4, 1923.

UNITED STATES PATENT OFFICE.

CHARLES J'. TTH, OF NEW YORK, N. Y., ASSIGNOR TO INTERNATIONAL PROCESS AND ENGINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW. YORK.

INTERNAL-COMBUSTION ENGINE.

Application led March 16, 1922. Serial No. 544,359.

To all whom it may concern:

- lle it known that I, CHARLES J'. TrH, a

citizen ofthe Republic of Uru uay, and resident of 322 West 57th -St.,lhew York city, o county and State of New York, have inventedcertain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

The invention relates to internal combustion engines, and particularly to such engines of the two cycle type. @ne of the objects of the invention is the provision of an improved engine of this type having its parts so constructed and'related as to provide for supercliargingl the cylinder. ln the present construction the exhaust ports of the cylinder are closed, cyclically, before the inletI ports are closed. The air or miriture thus continues to pass through the inlet ports into the cylinder during the interval heftvveen the closing of the exhaust ports and the closing of the inlet ports, and this continued charging of the cylinder after the exhaust ports have cosed is what is referred es to herein as the supercharging of the cylinder. the usual form of two-cycle engines such action is not possible, because of the fact that in them the exhaust. ports remain open until after the inlet ports have closed., so that no air or mixture can be -forced into the cylinder after the exhaust openings thereof have been closed, except by arrangements employing' a valve as in a Diesel type of engine, which valve is eliminated in the present invention'.

In attaining 'this super-charge a precompression chamber may he provided, in which chamber air or hydrocarbon fuel mixture, as the case may he, is compressed and tiren discharged into the combustion chamber through suitable ports.

In the embodiment oi the invention herein shown and described, this snpercharge is accom lished by providing,i 'two pistons operai',-

fi the cylinder, one being given a' lead the other, the niet coi'itrolling the exhaust ports while the sec-ond controls the ports; the arrangemenl: and construction of the p relative relation of the visions heling such that the ports are closed before the inlet ports are closed, and such that the exhaust ports are opened before the inlet ports are opened.'

In the preferred form vof the invention as herein shown, a duplex cylinder is used having parallel cylinder portions in which operate pistons connected by connecting rods of equal length to the'same throw of the crank shaft. rlhe parallel cylinder portions are so arranged with respect to the crank shaft as to glve one piston the desired lead over the other, and at the same time prevent either connecting rod from assuming such an angularity at any time as to impose excessive lateral stresses on the cylinder walls.

Another object of the invention is Ithe provision of improved precompression means, includingx in the preferred structure a precompression chamber beneath tliepistons in the cylinder and above and separate from the crank case, the pistons being provided with portions which controlthe ports of this chamber. A

According to this invention, extremely effective scavenging' may he had as Well as the desired supercharging above mentioned.

Other objects of 'the invention relate to the provision of improved features circonstruetion and combinations of parts, as' will be more fully set forth hereinafter'.

fin order that a clearer understanding of the inventionmay be had attention is hereby directed to the accoinpanying drawings forming part of this application and illustraining one embodiment of the invention. In the drawingsl represents a verlical section taken through an engine embodying` the invention;

Figs. 2 and 3 are sections taken respeci ely on line2- an,j ne 3--3 of Fig.

el is a vericai .tion laken @n.line

A iof Fig. 2; and

ig. 5 is diagram illustrating the opera-- tion of the engine.

Referring to the drawings, an iile combustion engine illustrated duplex cylinder whicl* r s 'Mall cylinder is provided with two parallel downwardly extending cylinder portion 3 and 4 arranged side by side, with a common combustion chamber 5 above the same. The crank shaft 6 is mounted in suitable bearings in the crank case and is provided with asingle crank or tlirow 7. Pistons 8 and 9 are mounted for reciprocation in the two parallel cylinder portions 3 and 4 and are connected by connecting rods 10 and 11 to crank 7, these rods being of equal length.

- ln Fig. 2 the intermediate portion 12 the sectlon line 4-4 lies in the vertical plane of the crank shaft. It will be noted from this drawing that parallel cylinder portions 3 and 4 are arranged with their vertical axes located respectively on opposite sides of and at equal distances from the vertical plane of the center line ot the crank shaft, said portions being staggered and overlapping one with respect to the other along the direction of the crank shaft. Accordingly these portions 3 and 4 are symmetrical with respect to the center line of the crank shaft, but overlap one another.

The cylinder portion 3 is provided with the exhaust ports-13, while the cylinder pon tion 4 is provided with the inlet ports 14.v

Cylinder portion 3 has an outer wall 31 spaced from the inner wall within which piston 8 operates, and cylinder `portion 4 has an outer wall 41 spaced from the inner wall in which piston 9 operates. Ports 13 and 14 extend through the inner walls of the cylinders (Fig. 2), and an exhaust outlet 131 in the outer wall 31 opens into the annular space 131, from which ports 13 extend into cylinder` portion 3. i

The piston 9, (Fig. 1) is provided with an inner hollow cylindrical portion 151, a top portion 161 and an outer concentric cylindrical portion 171. The piston 8 is similarly provided with portions 15, 16 and 17. This construction provides what I term a differential piston, because of the fact that the piston provides one area, the upper surface of the entire piston, to Serve as a working piston in the combustion chamber, while another, smaller area, an annular surface on the under side of the piston, serves aS a precompression piston, as will be explained hereinafter. A member 18, preferably a casting, is provided at the bottom of the two parallel cylinder portions 3 and 4, this member having cylindrical guide portionsy 20, 201, which constitute guides for the in ner cylindrical piston portions and 151.

Member 18 is also provided with horizontal flanges or diaphragm portions 2l, which serve to separate the interior of the crank case from a precompression chamber 27 provided above flanges 21, and hereafter to be described. ,l

The engine may be adapted to operate on a combustible mixturein which case the combustion chamber 5 will be provided with the usual spark plugs, or air alone may be drawn into the engine through the inlet ports and compressed to a considerable de gree in the combustion chamber, in which case fuel will be injected into the combustion chamber through fuel injectors, at suitable times, as is the practice in the Diesel type of engine. I have illustrated the cylinder head 22 as rovided with openings 23 in which spark p ugs or fuel injectors may be positioned. The upper portion of the cylinder may be suitably water jackcted, as is indicated at 24. The division wall 25 between the two parallel cylinder portions in which the pistons operate is illustrated in Fig. 4 as extending upwardly into the upper portion of the interior space of the cylinder.

Exhaust ports 13 are controlled by the portion 17 ot greatest diameter of piston 8 while the inlet ports 14 in the cylinder portion 4 are controlled by the portion 171 of greatest diameter of piston 9.

Ports 26'and 261, in cylinder portions 3 and 4 respectively, (see Fig. 3), serve as inlet ports for the precompression chamber 27, and are also controlled by the portions 17 171, of greatest diameter of the pistons 8 and 9, The precompression chamber 27, extends around cylinder portions 3 and 4, in the space above the horizontal flange 2l o member 18, Within the outer walls 31 and 41, and around the annular upwardly extending ilanges 20, 201, of member 18. An intake opening 28 leads through the outer wall 41 of cylinder portion 4 into the annular space 281, which extends around cylinder portion 3, between the inner and outer walls thereof, and partly around cylinder portion 4, between the inner and outer walls thereof, as shown in Fig. 3. The ports 26 and 261 are covered by the aprons or outer portions 17-171 of pistons 8 and 9 until, on

the upstroke of the pistons, the outer por-v tions 17-171 of the pistons begin to move past these ports, when air or mixture will be free to occupy the unobstructed space above ianges 21, between the outer .walls 31 and 41 and the inner cylindrical portions of the pistons. That is to say, the precompression chamber will comprise the space between inner and outer walls3 and 31, 4 and 41, the space below aprons 17, 171, and the'bottoms of inner walls 3 and 4, and the annular spaces between aprons 17, 171 and annular guides 20, 2,01, and between aprons 17. 171 and the inner cylindrical portions of the pistons above guides 20, 201, when the pistons are'raised above the positions shown in Figs. 1 and 4.

The'inlet ports 23, as shown in Fig. 3, may be positioned at intervals throughout the circumference of the cylinder portion 3. The ports 261 in the cylinder portion 4, howaio ever, may be positioned throughoutJ only a portion of the circumference of .cylinder portion 4, so that room may be left for free communication between the precompression chamber 27 and the inlet ports 14 which lead from the precompression chamber into the upper portion of the cylinder. This coinmunication is established when ports 14 are uncovered by the apron 171 ot piston 9, by way of the upwardly extending portion 271 of the chamber 27, which extends upwardly, at the right hand side of cylinder portion 4, to the level of ports 14, as is shown in Figs. 1 and 3.

From the above it will be evident that air or mixture will be drawn into the precompression'chamber 27 on the up strokes of the pistons when the aprons 17, 171, of the pistons have uncovered the ports 26 and 261. The air or mixture thus drawn into the precompression chamber will be compressed therein by the succeeding downward movement of the pistons, after the lower edges of the aprons 17, 171, of the-pistons have passed over and closed the ports 26 and 261. @peiling 28 will connect with the outside atmosphere when the engine is to be provided with fuel injectors and will be connected to suitable carburetin means when the engine is to be provided with spark plugs andv is to operate on the usual atomized mixture of air and fuel. It has not been deemed necessary to illustrate any connection from opening 28 to a carburetor or the like, since asstated the invention is applicable to both forms of e ne.

i he operation of the engine may be briefly described as follows. On the up stroke of the pistons air or mixture, asstated, will be drawn into the pi'ecompression chamber when ports 26 and 261 are uncovered towards the upper limit of the pistons. When the pistons again descend this air or mixture will be compressed within chamber 27 until piston 9 has nearly reached its lowest position on the down stroke, when ports 14 will be opened by whereupon the compressed air or mixture in chamber 27 Will pass through these ports` into the combustion chamber above the pistons..

Towards the endl of the down stroke of the pistons. that is the working or power stroke of the pistons, the p will be opened, shortly before the inlet ports 14 are opened, because of the fact that piston 8 has a lead over piston 9. There will accordingly be a scavenging action of the cylinder while both exhaust and inlet ports are opened, and until the exhaust ports 13 are again'closed on the next up stroke of the pistons. The lead of piston 8 on the down stroke is established because of the relative positjigns of the pistons and conf nesting rods with respect to the crank as the upper edge of piston 9,A

exhaust ports 13l previously described, it being understood that the crank is rotating in a right-handed direction, referring to Fig. 1.

The piston 8 also establishes a lead on the up stroke, so that exhaust ports 13 will be closed before the inlet ports 14 are closed. A period of supercharging then follows, the precompressed air or mixture in chamber 27 continuino' to pass into the combustion chamber of the cylinder for a period while the exhaust ports are closed. The inlet ports 14 are then closed and a period of compression of the air or mixture above both pistons follows. When the pistons are close to their uppermost positions the explosion or combustion of a combustible mixture takes place in the combustion chamber and both pistons again start downwardly on their working stroke.

The operation of the engine is best shown by the diagrams illustrated in Fig. 5, representing the relative positions of the-two pistons and the opening and closing of the various ports during one complete revolution of the crank. At the left of the ligure the dotted circle 29 represents the travel of the crank in a right-handed direction from its upper dead center position indicated at 1A, through 12A back to 1A, thirteen positions being thus indicated'. The positions of the connecting rods 10 and 11 at the upper dead center position are indicated by the dot-and dash lines 30 and 31, and the bottom dead center positions of the connecting rods are indicated bythe lines indicated in dash at 301 and 311. The positions of the connect- `ing' rods for the crank position 4A are indicated by the full lines 302 and 312, which indicate the lead which piston 8 has, established over piston 9 at that position, due todthe relative angularity of the connecting ro s.

The relative positions of the pistons are illustrated graphically by the line 32, shown in dash, representing the travel of the piston 8 whichcontrols the exhaust ports, and the full line 33 representingthe travel of the piston 9 which controls the inlet ports. The lines 32 and 33 start together from` the position 1A, as the two pistons start downwardly together on their working stroke. The line 32 passes through the various positions indicated by 2A1 etc., through 121, iinishing with the position 1A at the end of one revolution of the crank, while line 33, representing the travel of piston 9, passes throughthe positions indicated at 2A, etc., up to 12A, finishing at 1A -at the top of the stroke circle. Such a diagram is well known and its method of derivation need not be described.

Expansion of the gases doing useful work on the pistons, the exhaust ports being closed, takes place for, say, the First 1200 of the stroke cycle or from position 1A. to positions 5A and position 5A1. Atthe posiiro tion 5A1 the piston 8 starts the exhaust stroke by opening the exhaust ports 13. At a position intermediate positions 5A and 6A, which position I have indicated as 51, the piston 9 opens they inlet ports 14. The scavenging stroke accordingly begins'at this position 51, the mixture or fresh air admitted through ports 14 sweeping through the cylinder and driving the burned gases out through the exhaust ports 13 in the opposite portion 3 of the duplex cylinder. The scavenging stroke lasts until the position 81 is reached, intermediate positions 8A and 9A, the exhaust ports closing at position 81. The scavenging stroke thus continues through a. crank movement extending from position 51 to position 81 during which time both the inlet and exhaust ports remain open.

At position 81 the exhaust orts 13 are closed by piston 8 but the in et ports 14 .do not close until position 9A, so that the interior of the Workinv' cylinder will be surcharged with mixture or fresh air admitted from the precompression chamber 27 into the combustion` chamber; that is to say, during the period from position 81 when the exhaust closes until position 9A is reached the engine will have a so-called supercharge stroke. From the position 9A to the position 1A the compression of the mixture or fresh air in the combustion chamber of the working cylinder will be carried out.

The pistons 8 and 9 are arranged to open ports 26 and 261 to admit air into the precompression chamber 27 as stated, when the pistons are approaching their upper dead center position. These ports 26, 261, will accordingly be closed shortly after the pistons leave their upper dead center position on their down strokes, the air or mixture being compressed in chamber 27, beneath and adjacent to the outer portions of both pistons, during the down strokes oi' the pistons, the inlet ports 14 beginning to open when the position 51 is reached from which point, as stated above, the compressed mixture or air Will fiow from the precompression chamber into the combustion chamber above the pistons, untii the inlet ports again close at position 9A.

lt Wili be noted from the above description that the arrangement provides for an eiiicient scavenging and also for a. considerable snpercharge of the engine. It Will also be noted that the staggered relation ot the cylinder portions 3 and 4, with respect to the center line of the crank shaft, permits the vertical axes of the cylinder portions 3 and 4 to be brought fairly close to the center line of the crank shaztt as indicated in Fig. Q. The result oi this construction is that neither connecting rod need assume a position of considerabie angnlarity with respect to the axis of its cylinder so that the cylinder walls are not subject to the considerable lateral pressure which would be exerted on them, or on one of the cylinder portions 3 or 4, if the cylinder portions 3 or 4 were mounted directly opposite each other on opposite sides of the center line of the crank shaft.

It will also be noted that the arrangement provides for precompression o the air or mixture within the cylinder structure itself, the pnecompression chamber thus formed being much smaller than the space for precompression which would be afforded if the air or mixture were precompressed. in the crank case, as has previously been done. Accordingly a higher degree 0i precompression may readily be secured while at the same time the necessity of making the crank case air tight is obviated.

It will also be observed that the arrangement of differential pistons provided in the form of invention illustrated aords an effective means for controlling the inlet ports, exhaust ports and intake ports leading to the precompression chamber, one of the differential pistons controlling the exhaust ports While the other controls the inlet ports leading to the combustion chamber, and both of the diierential pistons controlling the inlet ports leading to the precompression chamber.

It should be understood that the invention is not limited strictly to the detaiis o construction Which have particniarly described but that various equivalents of the constructions described are included Within the invention, the scope of the latter being indicated by the accompanying claims.

1. In an internal combustion engine, the combination of a crank shatt, a dupiex cylinder having a common combustion chamber and parallel portions arranged symmetricaiiy with respect to the center line of ythe crankshaft with their center iines on opposite sides thereof, pistons in said paralisi cylinder portions and connecting rods of equal length connecting said pistons with portions of the same crank o/said crankshaft separated in the iengthwise direction of said crankshaft, one oi' said parallel'cylinder portions having an exhaust opening saine having crankshaft, and connections between said crankshaft and pistons arranged to cause the exhaust port to be opened or closed respectively' -by one piston before the inlet port is opened or closed by the other piston, said cylinder elements being staggered in the axial direction of the crankshaft and arranged symlnetrically with respect to the center line of the crankshaft.

3. In an internal combustion engine, the combination of a crankshaft, a duplex cylinder having parallel portions extending at right angles to the axis of said crankshaft, with their center lines on opposite sides of the center line thereof, at equal distances therefrom, and said portions, being staggered in the axial direction of the crankshaft, pistons in said parallel portions, and connections between said pistons and the same throw of said crankshaft.

4. In an internal combustion engine, the combination of a duplex cylinder having two working portions, one having'an exhaust port and the other an inlet port, the cylinder being arranged to provide a pre-compression chamber, having inlet ports, in both portions, and pistons in said working cylinder portions, one of which controls the exhaust and the other the cylinder inlet port, while both of them control theopening and closing of the precompression chamber inlet ports.

5. In an internal'combustion engine, the combination of a duplex cylinder having two working portions, one having an exhaust port and the other an inlet port, and differential pistons in said working cylinder por tions, precompression spaces, connected together, bein@r provided in both cylinder portions beneatli said pistons, the said cylinder inlet port opening into said space and being controlled by one of said pistons, and both working portions of said cylinder having intake openings leadin into said space, controlled by both of sai pistons.

6. In an internal combustion engine, the combination of a crank shaft, a duplex cylinder having parallel portions arranged with their center lines on opposite sides of the center line of the crank shaft, at equal distances therefrom and said portions being staggered and overlapping each other in the axial direction of the crank shaft, pistons in said parallel portions and connections between said pistons and crank shaft.

7. In an internal combustion engine, the combination of an engine structure having a pair of cylinder elements connected together to provide a common combustion chamber at one end and a precompression chamber at the other end, one of said cylinder elements haying an exhaust port and the other having an inlet port extending into the same from said precompression chamber, said precompression chamber having an inlet port, pistons in said cylinder elements arranged to open and close said cylinder inlet and exhaust ports and to precompress gaseous mixture in said precompression chamber, a crankshaft and connections arranged to cause one piston to obtain a lead over the other, each stroke, to cause the exhaust port to be opened and closed, respectively, by

said piston, before the cylinder inlet port is opened and closed, respectively, by the other piston, one of said pistons controlling the pre-compression chamber inlet port.

8. In an internal combustion engine, the combination of a crankshaft, a pair of cylinder elements connected together to provide a common combustion chamber, precompression spaces being provided in both cylinder elements, connected together, said precompression spaces having inlet ports, one of said cylinder elements having an exhaust port and the other having an inlet port connecting with one of said precompression spaces, pistons in said cylinder elements arranged to open and close said cylinder inlet and exhaust ports, respectively, and both pisons being arranged to open and close sai crankshaft and connections between said crankshaft and pistons arranged to cause the exhaust port to be opened and closed, respectively, by one piston, before the cylinder inlet port is opened and closed, respectively, by the other piston.

In testimony whereof -I have signed my name to this specification at N ew York, N. Y., this 15th day of March, 1922.

` CHARLES J. TTH..

precompression space inlet ports, a` 

